Jump to content


Welcome to DBSTalk


Sign In 

Create Account
Welcome to DBSTalk. Our community covers all aspects of video delivery solutions including: Direct Broadcast Satellite (DBS), Cable Television, and Internet Protocol Television (IPTV). We also have forums to discuss popular television programs, home theater equipment, and internet streaming service providers. Members of our community include experts who can help you solve technical problems, industry professionals, company representatives, and novices who are here to learn.

Like most online communities you must register to view or post in our community. Sign-up is a free and simple process that requires minimal information. Be a part of our community by signing in or creating an account. The Digital Bit Stream starts here!
  • Reply to existing topics or start a discussion of your own
  • Subscribe to topics and forums and get email updates
  • Send private personal messages (PM) to other forum members
  • Customize your profile page and make new friends
 
Guest Message by DevFuse

Photo

A Tale of Two Towers


  • Please log in to reply
11 replies to this topic

#1 OFFLINE   Nick

Nick

    Keep going - don't give up!

  • DBSTalk Club
  • 21,217 posts
  • LocationThe Beautiful Golden Isles of Coastal Georgia
Joined: Apr 23, 2002

Posted 02 November 2009 - 05:49 PM

Alaska station KUAC makes unusual DTV switch - goes from UHF to VHF

From B&C

After full-power broadcasters ceased analog operations on June 12 and settled into their final digital TV (DTV) assignments, one of the early findings was that stations with VHF channel assignments were experiencing far more reception problems than their UHF counterparts.

Reception issues were particularly prevalent in Eastern cities like Philadelphia and New York, where the number of stations in close proximity meant that VHF stations had to curtail their power to avoid interference and were often left with signals unable to penetrate into apartment buildings for reception on small indoor antennas...

But at least one station, KUAC Fairbanks, Alaska, decided to move in the other direction to solve its reception problems. The public broadcaster actually switched in late September from a DTV assignment on UHF Ch. 24 to VHF Ch. 9, its previous analog home, undergoing a “rechannelization” process that required it to go off-air for six days...

The Fairbanks market never had a UHF station until stations began broadcasting DTV. So when KUAC began broadcasting DTV on Ch. 24 in 2004, it didn't expect many viewers to have the proper UHF antenna required to receive the signal. The station also had a relatively low-power allocation for UHF of 79 kilowatts ERP (effective radiated power), and actually went on-air at a licensed power of 69 kW. Initial tests showed reception problems at a range of only 11 miles from the transmitter...

More @ Broadcasting & Cable.com

.


~ 12 Year Anniversary Month ~
Charter Gold Club Member
DBSTalk Club ~ 21k Club
Top 10 Poster

.


...Ads Help To Support This SIte...

#2 OFFLINE   AntAltMike

AntAltMike

    Hall Of Fame

  • Registered
  • 2,712 posts
  • LocationCollege Park MD (just outside Wash, DC)
Joined: Nov 20, 2004

Posted 02 November 2009 - 06:24 PM

If it is an "unusual switch", it would only be so because I think most of the VHF highband channels chose to use VHF highband as their final channel, making fewer available for other stations to choose.

At one time, the conventional wisdom was that VHF highband (channels 7-13) was the best channel group to be used because they bent over hills better than UHF and used less electricity for their transmitters, but there was so much less impulse interference than there was in the lowband (2-6). What many were surprised to learn was that the impluse speckles that had gone unnoticed in analog VHF high become very noticable when they cause a one second or more frame disruption. Also, I think most broadcasters did underestimate just how many people would be using set top antennas rather than rooftop, but it is often impractical for a viewer to have a 30" wide antenna with a 4 foot boom on top of his TV.

From the linked article:

The problems suffered by high-V stations like WCPO Cincinnati are somewhat ironic, says Scripps’ Doback, as several years ago stations with a high-V assignment thought they would “be in heaven” because of the expected combination of good signal propagation and low power costs.

“It’s only now that we’ve found out the planning factors were probably wrong in terms of how much power you need to replicate analog service,” says Doback.e) Doback, (VP of engineering for Scripps).


Edited by AntAltMike, 02 November 2009 - 06:31 PM.


#3 OFFLINE   n3ntj

n3ntj

    Hall Of Fame

  • Registered
  • 5,697 posts
Joined: Dec 18, 2006

Posted 03 November 2009 - 10:29 AM

Too bad WPVI in Philly can't go back to UHF... I haven't been able to watch them since June 12th when they left UHF to go back to channel 6. Even with the power increase the FCC approved, many of us near Philly still can't get that station.
HD Snob - "Friends Don't Let Friends Watch Cable".
Electrical/RF Engineer & Inspector
DirecTV Equipment: HR24-200, HR24-100, 5LNB Slimline, AM21, SWiM 8 installed (MRV)
HR-2x Configuration: Native OFF. Units OFF when not in use.
TVs: 2 Panasonic Plasma TV's each using HDMI (one 1080p/one 720p)
DirecTV customer since 1998. Plus HD DVR package w/ NHL Center Ice & MLB Extra Innings.
OTA Antenna: Homebrew UHF & VHF antennas w/ 30dB amplifier fed w/ RG-6 Quad-shield coax.

#4 OFFLINE   Tower Guy

Tower Guy

    Godfather

  • Registered
  • 450 posts
Joined: Jul 27, 2005

Posted 05 November 2009 - 08:03 PM

Too bad WPVI in Philly can't go back to UHF... I haven't been able to watch them since June 12th when they left UHF to go back to channel 6. Even with the power increase the FCC approved, many of us near Philly still can't get that station.


Especially when they have an antenna in the attic and are located in the adjacent TV market.

Edited by Tower Guy, 06 November 2009 - 11:43 AM.


#5 OFFLINE   wilbur_the_goose

wilbur_the_goose

    Hall Of Fame

  • Registered
  • 4,390 posts
Joined: Aug 16, 2006

Posted 08 November 2009 - 07:52 PM

TowerGuy - what do you mean by "in the attic"?

I'm still miffed at 'PVI for choosing VHF-Lo

#6 OFFLINE   Tower Guy

Tower Guy

    Godfather

  • Registered
  • 450 posts
Joined: Jul 27, 2005

Posted 09 November 2009 - 09:52 AM

TowerGuy - what do you mean by "in the attic"?

I'm still miffed at 'PVI for choosing VHF-Lo


Those who have trouble with 'PVI usually have a compromised antenna. It's either in a poor location or the wrong type of antenna.

n3ntj has his channel 6 antenna in the attic. That's not 'PVI's fault.

#7 OFFLINE   n3ntj

n3ntj

    Hall Of Fame

  • Registered
  • 5,697 posts
Joined: Dec 18, 2006

Posted 18 November 2009 - 12:15 PM

I actually did try the antenna first outside (before I rebuilt it in the attic) and still couldn't get WPVI. I am within WPVI's service territory according to the FCC data.
HD Snob - "Friends Don't Let Friends Watch Cable".
Electrical/RF Engineer & Inspector
DirecTV Equipment: HR24-200, HR24-100, 5LNB Slimline, AM21, SWiM 8 installed (MRV)
HR-2x Configuration: Native OFF. Units OFF when not in use.
TVs: 2 Panasonic Plasma TV's each using HDMI (one 1080p/one 720p)
DirecTV customer since 1998. Plus HD DVR package w/ NHL Center Ice & MLB Extra Innings.
OTA Antenna: Homebrew UHF & VHF antennas w/ 30dB amplifier fed w/ RG-6 Quad-shield coax.

#8 OFFLINE   xcellu8

xcellu8

    New Member

  • Registered
  • 1 posts
Joined: Nov 18, 2009

Posted 18 November 2009 - 03:45 PM

I heard some DTV stations cut their power by over 90%, making reception nearly impossible.

Many stations that have reverted to VHF assignments have dramatically cut their transmitter power, in some cases by over 90%! Some stations mistakenly thought they could save money by cutting their power while reaching the same number of viewers.http://getting-vhf-s...s.blogspot.com/



#9 OFFLINE   Jim5506

Jim5506

    Hall Of Fame

  • Registered
  • 3,443 posts
Joined: Jun 07, 2004

Posted 18 November 2009 - 07:00 PM

If they moved from UHF to VHF, the propagation of VHF is so much better that the FCC limits them to less than 200kw, whereas some UHF stations were flaming 5,000kw.

Most reception problems are a factor of poor antenna, poor location and poor installation.
Tuners: Hopper 2000; Hopper w/Sling; 3 Joeys; Samsung SIR-T351; Accurian 6000;2 X HD TiVo; 2 X TiVo Series 2 Stand alone; Panasonic Showstopper 2000
Dish 1000.2 @ 110, 119, 129; dish 500 @ 61.5
Antennas - CM4228; RS U75-R; coathanger; Funke PSP.1922 (stillin the box); paperclip
Displays: Sony VPH D50Q with HD Fury HDMI input; Hitachi 57F59; Sony Bravia LCD;Sanyo 32" LCD; Panasonic 42" plasma
Sony 80GB PS3; Toshiba HD-DVD

Give me a Finco colinear array and I'll rule the world - HA-HA-HA-HA!

#10 OFFLINE   Jerry Springer

Jerry Springer

    Mentor

  • Registered
  • 30 posts
Joined: Jun 24, 2009

Posted 20 November 2009 - 09:37 AM

In most for instances, the station that moved from UHF to VHF - were a Fox affiliate and did not have the deep pockets such as a mainstream corporation such as ABC, NBC, CBS.

If you was to use Great Britain as a model, you would see that for the most part, they only need one antenna on their roof. With the proper method for direction - a Rotor, they can watch all the channel available.

When they do need amplification to receive as many Free View channels as possible, they use a highly sensitive amplifier to receive their signals with little problem from over load due to the fact that they do not have to have a VHF amplifier and FM radio does not interfere with their reception.

On a DX email the other day, I told a station congratulations for their signal making it 120 miles north in Appalachia - West Virginia to Pennsylvania through the mountains.

We talked a little and when I offered assistance - if they needed any tech support they got real quiet. I didn't know why until later in the day when a family member told me that they owed his company money and that they told him that they would like to pay their bill - since it was 90 days over due, but that their station was hemorrhaging $100,000 a month and they did not know how much longer they would be able to keep the lights on.

This is a small 10kw station on channel 5.

Now you tell me, when the car dealers and the grocery stores and the furniture stores all stops advertising how you can pay the electric bill when you have a 5,000 KW station that is using $18,000 a hour of electricity?

Many stations are going to have to either move down to the VHF where electricity costs are less or go out of business. OBAMA's plan to save this country is not working. The people who had jobs - either are hanging on by a thread or are out of work or are underemployed and living beyond their means.

With many stores starting their Christmas season early this year and many store telling us that they are going to try to do more with less and are not going to hire seasonal help to get them through the Christmas season, many familys are going to have a very green Christmas this year. It's all a trickle down, like stepping on a butterfly 1000 years ago and changing the history of the world.

#11 OFFLINE   Jerry Springer

Jerry Springer

    Mentor

  • Registered
  • 30 posts
Joined: Jun 24, 2009

Posted 20 November 2009 - 09:45 AM

The DTV transition could not have come at a worse time in history.

With the country in a recession and money tight and advertising dollars drying up and broadcasters having to spend trillions of dollars to put up new transmitters and antenna's and consumers having to spend Billions of dollars on new televisions or converter boxes.

If the government would have left the UHF band alone and just took away the VHF - we would not have all the reception problems we have today.

But just like others has said on this post, when consumers refuse to listen to good advice and trys to put their antenna in the attic, because they do not want a big, ugly, antenna on their roof. Status symbol of the poor, and when they do not want to properly point their antenna in the right direction (rotor), the will find that they will have more problems then they can solve with a Ebay or Walmart $50 amplified antenna.

It is better to use one really good antenna and some amplification and point it in the right direction if needed to receive all your signals, then to put up 3 antenna's and deal with multipath and poor reception. Or use a small antenna and then try to amplify the signal to make up for the poor reception of the small antenna.

People do not realize that the antenna looks really big down on the ground, but doesn't look so bad, once it is 10 feet above the roof.

Some people just does not want to spend the money. They understood how the VHF analog worked, but do not understand how the digital UHF works and all they want is a set of rabbit ears antenna on top of their television and when it does not work, they are calling the stations and demanding that they turn up the power so that they think that the signal will travel further and will require less of a antenna to receive it.

#12 OFFLINE   DF Wavelength

DF Wavelength

    Mentor

  • Registered
  • 46 posts
Joined: Apr 29, 2009

Posted 20 November 2009 - 09:49 AM

If they moved from UHF to VHF, the propagation of VHF is so much better that the FCC limits them to less than 200kw, whereas some UHF stations were flaming 5,000kw.

Most reception problems are a factor of poor antenna, poor location and poor installation.


Here in Denver the local ABC & NBC affiliates moved back into the VHF High Band during the switch in June. They completed their transition overnight.

The VHF channels are transmitting at only 45 kW, while all the UHFs are set to 1000kW.




spam firewall